Now and then individuals are met with, seemingly actuated either alternately or simultaneously by two different and distinct personalities. The personality usually predominating is regarded as the normal, or primary personality, while the one less prominent or less frequent and complete in manifestation is known as the secondary personality. The appearance of the latter may bo frequent, periodical or rare. When such manifestations result from internal or functional causes, they are considererd natural, but when due to personal manipulation of external conditions, they are spoken of as induced. In hypnotism we find the individual actuated by a strange and apparently independent personality, neither known to nor knowing the normal personality, a condition induced usually by an operator who alternates the two personalities at will and who possesses power of control, more or less complete, ever the secondary personality. In cases of automatic writing, planchet writing, etc., we find two distinct personalities working simultaneously, but independent of and unknown to each other. In the latter, no operator is necessary as the secondary personality will communicate with any one in its chosen way, or express ideas when no one is present.

It thus appears that hypnotism is a particular kind of phenomena belonging to a more general class.

The so-called hysterical eye presents an interesting case of double personality. In such an eye the normal field of vision is greatly narrowed so that objects falling slightly to one side of the retina are not seen as in the normal eye. Yet, if a pencil be placed in the hand of a person so afflicted and the attention fully occupied elsewhere, the hand will often proceed to record what falls upon the apparently blind part of the retina, while its owner is ignorant of the whole affair. Here we have a secondary personality able to receive impressions too weak to reach the other.

In ordinary cases of automatic writing the impressions are received through the ear.

Attempts have been made to induce automatic writing in normal persons with some show of success, but so far as the writer is aware no such cases have gone far enough to put the eye or ear in rapport with the hand, so as to furnish a clear case of induced double personality That such is possible the following experiments seem to indicate.

In the first place, let us see if the eyes of normal persons can be trained to act in a manner similar to the hysterical eye. Dr. Scripture, of Yale, made a few observations upon unconscious association, that give us a hint as to how to approach this problem. He mounted pictures upon cards, in one corner of which a small letter was printed, so that when the subject was looking at the picture the small letter would fall upon the indirect field of the retina. Eye movements were avoided and the letter made invisible by exposing the card for an instant only. After seeing the picture, the subject was asked what letter it suggested to him. As a great many answers agreed with the letter in the corner of the card, the conclusion was reached that association might take place between things consciously seen and those not so seen.

Similar tests were made by the writer. The cards used carried rather complex geometrical figures of the same size. Upon the right end of the card a letter or numeral was printed. The card was exposed by a quick acting shutter, and a fixation point served to keep the eye of the subject in the proper position. In the preliminary experiments the subject was requested to close his left eye and fix his right upon the point where the figures would appear and to take note of them as they were exposed. Three cards were shown in succession, after which they were repeated in a series of four and at each exposure the subject was required to say whether he had seen the figure in the former series, and then requested to name the first letter coming to mind. The purpose and conditions of the experiment were unknown to the subjects, they being led to believe my object the testing of their ability to recognize geometrical figures and the determination of what they first associated with them. Because of this they fixed their eyes so intently upon the place where the figures were to appear that the presence of characters on the end of the card was not discovered.

Thus the conditions of fixed attention essential to automatic writing, etc., were secured.

Six young men, college students, were taken for the preliminary trials. With two of them the number of correct.answers far exceeded the limits of chance, while the others did no better than if they had simply drawn letters from a hat. So far we have simply tested Dr. Scripture's conclusions and found them true, at least for some individuals.

The two promising subjects, C and R, were then practiced with daily for several weeks with decided improvement in the number of correct answers. As was to be expected C and R soon found the letters coming into mind shortly after the presentation of the card. According to their own statements the change came about in this way. As the differences between the complex geometrical figures were small, they found it difficult to remember them in detail. So while the experimenter was changing a card they would visualize the preceding. It was not long until the letters would also come into mind for the association. A little later the letter would come as soon as the figure was seen in the first presentation. From this it appeared that association of memory images was not necessary to bring impressions of the marginal letters into consciousness and the method was changed accordingly. Pictures were substituted for the geometrical figures and numerals were used in the margins. The subject was to name the picture as quickly as possible and then give the numeral sug-gested. Between each exposure the subject was engaged in conversation to break up any trains of association set going by the previous one, and to prevent him falling into that state of mind best described as "wondering what the next will be."